Dry cleaning apparatus



July 14, 1970 A. DONINI ETAL 3,520,157

' DRY CLEANING APPARATUS Filed April 12, 1968 INVENIORS Attilio 7 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a dry cleaning apparatus comprising at least one container for the solvent, a washing tank and a washing cage rotating within the washing tank, .auxiliary hydraulic circuits for recovering and regenerating the solvent, at least one pump for circulating the solvent, at least one main filter for said solvent.

= BACKGROUND OF THE INVENTION This invention relates to a dry cleaning apparatus.

j In dry cleaning apparatuses use is made of a solvent, such as tri-chloroethylene or perchloroethylene, which is introduced into a washing tank in which a rotating cage or drum containing the garments to be washed is partially immersed. In certain types of dry cleaning apparatuses the rotating drum or cage is not immersed in the solvent, but the solvent is sprayed on the garments to be Washed.

The solvent contained in a tankis circulated by means of .a pump and prior to entering the washing tank the solvent is passed through filter means.

In cleaning apparatuses the filtering is of utmost im portarice.

Usually the filtering of the solvent is carried out in two stages. First the solvent is passed through a primary filter of rough structure to separate the particles of great size and afterwards the solvent is passed through a main filter having a fine structure. Usually the circulating pump is placed betwen the primary filter and the main filtering group, directing the flow of solvent in the direction from the primary filter to "the main filter group.

Thefilters usedindry cleaning apparatuses comprise a supporting permeable structure for layers of a filtering powder of fossil origin, called fossil meal. The filters of this type are well-known in the art and will not be described more in detail, since they perv se are not a part of this invention. The permeable structure for supporting the layers of fossil meal will be hereinafter called armature.

In such filters, prior to the washing cycle of the apparatus, it is necessary to treat or process either partially or completely the layers of fossil meal, depending on the mechanical structure of the filter. Such treatment or processing of the fossil-meal layers consists in stirring and re-depositing of the fossil meal layer on the armature after'a previous dissolution or additioning of fresh fossil meal. Such processing of the fossil-meal layers may also consist in depositing a very thin layer of fresh fossil-meal over the previous layer of fossil-meal.

Such processing of the layers of fossil meal required special auxiliary devices and circuits in the dry cleaning apparatuses, so that the construction of such machines became very' complicated and the manufacturing and operative costs thereof remarkably increased, owing also to the increased number of hydraulic circuits involved and the consequent increased number of expensive valves to' be operated.

In the conventional dry cleaning apparatuses independent hydraulic circuits for processing the fossil-meal layers have been adopted, in order to prevent that portions of United States Patent ice fossil meal contaminate the remaining parts of the other hydraulic circuits existing in such apparatuses and to prevent formations of deposits of fossil-meal and wastes in containers from which a removal is difiicult.

SUMMARY OF THE INVENTION An object of this invention is to simplify the dry cleaning apparatuses of the described conventional type without impairing the functional quality thereof and allowing the possibility to regenerate the filters and the filtering material.

Another object is to reduce the manufacturing and operating costs of such apparatuses.

These and other objects are attained by a dry cleaning apparatus according to the invention, comprising auxiliary hydraulic circuits for recovering and regenerating the solvent, at least one container for the solvent, a washing tank and a washing cage cooperating with the washing tank, at least one pump for circulating the solvent, at least one main filter for said solvent wherein the improvement comprises a compartment communicating hydraulically with said container for the solvent, said pump having its intake portion within said compartment and having its delivery portion directly connected with the inlet of said main filter, said main filter having its outlet opening directly connected with said washing tank, said washing tank having a discharge communicating hydraulically with said compartment, said compartment containing primary filter means for said solvent, and means for regenerating said main filter connected in series with the delivery side of said pump.

BRIEF DESCRIPTION OF THE DRAWING Further features and advantages of the invention will appear from the following description of a preferred embodiment of thei invention, illustrated by way or example in the accompanying drawing, in which the single figure shows a diagrammatic representation of the embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawing, within the interior of the container 1 for the solvent there is provided a com partment 2 which communicates with the interior of the container through a long pipe 3, which extends from the bottom of the compartment 2 and ends at the lowermost part of the bottom 4 of the container 1. The bottom 4 is sloped towards the portion wherein the pipe 3 opens. Placed between the compartment 2 is a pump 5 of the type operating under immersion, the intake 6 of which, is arranged slightly above the bottom of the compartment 2 and at the side thereof, opposite the one from which the pipe 3 extends. The pump 5 is actuated by an electromotor 7 and has its delivery pipe 8 directly connected with the inlet of the main filter 9. This filter is of the type in which the layers of fossil meal are regenerated by progressively increasing such filtering layers with new deposits of fresh fossil meal, which is introduced after each washing cycle and which deposits on the previous fossil meal layers.

The outlet pipe 10 of the filter 9 leads directly towards the washing tank 11, within which is arranged the rotating cage or drum 11a having an opening 11b and containing the garments to be washed and adapted to rotate about a horizontal axis. Extending from the bottom of said tank 11 is a pipe 12, having a hand operated valve 13 interposed therein and reaching through a pipe section 14 a collecting member 15 arranged above the compartment 2 and constituted of a tubular section the top of which is closed by a lid 16. Within said tubular section 15 a rather elongated and deep cage 17 may be placed, which is made of a metallic net having relatively small sized meshes.

The aforementioned cage 17 rests on a shoulder 18 of the member and is almost interposed between the intake of the pump 5 and the mouth of the pipe 3 opening into the compartment 2.

Hydraulically connected with the container 1 are also hydraulic circuits for recovering the solvent, which are constituted of a circuit capable to transform into liquid condition the solvent egressing from the tank 11 during the drying and regenerating stage of the solvent. The recovering circuit comprises a conduit 19 which opens into the tank 11 and through which hot air is introduced during the drying stage, a conduit 20 extending from the tank 11 and leading to the condenser 21 the discharge 22 of which is connected through the pipe 23, the inspection hole 24, a device 25 capable to separate water, if any, from the solvent, the valve 26 and a pipe 27 with the container 1. Leading to the condenser 21, i.e. the liquid phase collector provided in said condenser 21, is an outlet pipe 28 of a second condenser 29, in which enters the vapour of the solvent created in the still 30, placed above the container 1 and which is connected, through a manually actuated valve 31, with the lower part of filter 9.

The operation of the apparatus is as follows.

Supposing the apparatus just installed and the container 1 filled with a pre-established quantity of solvent, it is first necessary to prepare the filter 9 for operation. This is done by introducing into the cage 17 a suitable quantity of fossil-meal and by actuating the pump 5. The latter sucks the solvent from the compartment 2 and conveys the solvent entering the compartment 2 through the pipe 3 towards the filter 9. The current of the solvent which is created within the compartment 2 entrains the fossil meal contained in the cage 17 through the meshes thereof and conveys this fossil meal through the pump towards the filter 9. The thus entrained fossile meal is deposited on the internal armatures or supporting structure of the filter 9 thereby forming progressively a uniform layer of fossil meal therein. The solvent which entrained the fossil meal into the filter egresses from the filter, after the fossil meal has been deposited in layers, and reaches the tank 11 devoid of solid particles. From tank 11, through conduit 12, open valve 13, pipe section 14 and collector member 15 and cage 17 the solvent reaches again the compartment 2. In this way after a certain time from the beginning of the operation, the solvent enters the compartment 2 both from the discharge conduits of the tank 11 and from pipe 3.

After the pump has functioned a certain time, i.e. at the moment in which within the tank 11 a solvent level has been established which determines an egressing flow through the discharge conduits, which is equal to the flow of solvent delivered thereto by the pump, no solvent is sucked any more from the container 1 and the subsequent circulation tf the solvent occurs as if only a closed circuit existed, comprising the compartment 2, the pipe 8, the filter 9, the pipe 10, the tank 11 and the discharge thereform.

At this stage the initial preparation of the filter is attained and the pump may be stopped. The garments to be cleaned are then introduced into the cage arranged in the tank 11 and the pump 5 is again actuated. The circulation of the solvent occurs then in the previously described manner, when the equilibrium is attained between the solvent flow egressing from and the solvent flow entering the compartment 2, i.e. when a steady flow is attained during the entire washing cycle.

. Upon the termination of the effective washing stage, i.e. when the pump stops, the solvent returns into the compartment 2 and therefrom into the container 1. When the flow of solvent from tank 11 stops it is possible to start the subsequent drying and deodorization stages. During the drying stage the generated solvent vapour is conveyed into the condenser 21 and after the condensa- 4 tion therein the solvent is conveyed to the container 1 through the conduit 23, past the inspection hole 24, through the separator 25, the valve 26 and the pipe 27.

After a certain number of washing cycles it is necessary to completely renew the filter 9. For the purpose such filters are provided with a per se known mechanism which causes the scaling of the layers of fossile meal, which increased progressively by virtue of the type of regeneration through which upon every washing cycle a new layer of fossil meal is deposited onto the previous layer. Such mechanism is manually actuated in these filters and through this actuation the fossil meal is suspended in the solvent residue which remains within the filter. The entire content ofthe filter is then discharged into the underlying still, by opening the valve 31.

After that, the apparatus may again operate in the previously described manner by first depositing a new layer of fossil meal in the filter 9.

The solvent discharged in the still 30 is distilled only after the filter 9 has been completely cleaned a preestablished number of times, i.e. after the solvent level in the still 30 has reached a pre-established height. Then the solvent in the still 30 is evaporated and condensed through condenser 29, while the remaining fossil meal is discharged. 7

It will be appreciatedthat this apparatus allows both a partial and a total regeneration of the filter.

It will be further appreciated that the valve 13 permits to vary the level of the solvent within the tank 11', since the throughput of the pump 5 is approximately constant for each washing cycle. The level of the solvent within the tank 11 is approximately inversely proportional to the area of the passage defined by the valve 13.

The direction of the flow of solvent within the pipe 3 connecting the container 1 with the compartment 2 and the length of this pipe prevent any appreciable diffusion of the fossil meal into the container 1.

We claim:

1. Dry cleaning apparatus comprising auxiliary hydraulic circuits for recovering and regenerating the solvent, at least one container for the solvent, a washing tank and a washing cage cooperating with the washing tank, at least one pump for circulating the solvent, at least one main filter for said solvent wherein the improvement comprises a compartment communicating hydraulically with said container for the solvent, said pump having its intake portion within said compartment and having its delivery portion directly connected with the inlet of said main filter, said main filter having its outlet opening directly connected with said washing tank, said washing tank having a discharge communicating hydraulically with said compartment, said compartment containing primary filter means for said solvent, and means for regenerating said main filter connected in series with the delivery side of said pump and including a normally closed discharge opening for the main filter and distillation means for the solvent discharged therethrough.

2. Apparatus according to claim 1, characterized in that said compartment is in the form of a well provided in the interior of said container, and wherein a pipe of substantial length is provided, hydraulically connecting said well with said container.

3. Apparatus according to claim 2, characterized in that said container has a sloped bottom and has a sump formation 'at the lowermost portion of said bottom and wherein said pipe connecting the container with said well opens into said sump formation.

4. An apparatus according to claim 1, characterized in that it comprises further a pipe connecting said washing tank and said compartment, said pipe having a manually operated valve interposed therein and controlling the flow of solvent through said pipe.

5. Apparatus according to claim 1, characterized in that said primary filter comprises a cage having walls of net structure, said cage containing fossil meal for the References Cited regeneration of the main filter.

6. Apparatus according to claim 5, further comprising UNITED STATES PATENTS a tubular member arranged near said compartment and 2 140 2 12 19 Hetzer 68 18 X collectlng the solvent from said washing tank, said tubular 2,359,138 9/1944 Martin 68 18 member having at the top thereof a lid member covering 5 3 168 178 2/1965 Stone et a1. X its upper end, said tubular member supporting said cage. 3250O98 5/1966 Lana et a1 68*18 7. Apparatus according to claim 5, characterized in 3306O83 2/1967 Lorgitzo 68 12 that said cage is placed within said compartment between the intake of the circulating pump and the mouth of the pipe connecting said compartment with said container. 10 WILLIAM PRICE Pnmary Exammer 

